1. Course Overview Genetics Regeneration & Seed Production
Tree Structure & Growth
shape, stem (bark & wood), roots, leaves
Bioclimatology
temperature, water, solar radiation
Water
Carbon
Soil Properties
physics (water)
chemistry (nutrient availability)
Stress Physiology & Dormancy
Site Quality & Growing Seasons
The book covers many ecosystems, we will be focusing our attention on trees.
This is a general outline of the class, and we will adjust accordingly. If there
is time at the end of the class, we will cover fire.

2. Components of Landscape Ecosystems
Entity
Inorganic and
Organic Components
Ecosystem
Abiotic
Components
(Physical
environment = site)
Climate (macro- and microclimate)
Physiography (form of land and
parent material)
Soil (edaphic factors of water, air,
nutrients, etc.)
Biota
(Biotic
community)
Plants – Plant communities
Animal - Animal communities
Microbes - Microbial communities
What is an ecosystem?
A. Ecosystem - community of organisms interacting and functioning together through:
1. Flow of energy
2. Cycling of energy

3. This is a diagram of an ecosystem from 1962.
It is somewhat surprising that we had such a good
understanding of ecosystems back then. Basically,
all we have done since is fill in the boxes themselves.

4. This is more of what we see today – lots of
boxes and arrows. This class is designed to
gain a first understanding of the boxes AND
arrows.

5. Tree Genetics

6. Influences on plant development
genotype = the exact genetic makeup of an individual
environment (climate, parent health, soil fertility)
Phenotype = influence of BOTH genotype and environment +

7. The effect of environment on genetics
Northern Red Oak
Notice how much effect environment can have on the
Northern Red Oak, while the Shingle Oak is less affected.
Shingle Oak

8. The effect of environment on genetics
Sitka Spruce
This is the same species. There is a
dramatic change of 50+ days in cessation
of growth from the southern to the
northern latitudes.

9. Plasticity of phenotype
Size of vegetative parts
Number of shoots, leaves, flowers
Stem elongation rate
Photoperiodism
Non-plastic
Leaf shape
Serration of leaf margin
Floral characteristics
Those characteristics created over a long period of time
tend to be more plastic than those created rapidly.

10. Niche Where? When? How? Spatial component Temporal component
“a habitat supplying the factors necessary for existence” or
“the ecological role of an organism in a community”
Where?
Spatial component
When?
Temporal component
How?
Functional component
Definition is from M-W.
Where…
Where is this species able to exist? Is this species largely
found in the Southern U.S. (Loblolly pine) or the northern U.S. (Douglas
fir)? Does it exist only in floodplains (e.g., cottonwoods) or in drier areas
(Juniper)? How dependent is this species on a given set of conditions?
When…
When does this species dominate at a given site? Is it
found at the site early in succession (birch, lodgepole pine) , or is it a
species which is only found after a site has been under development for
some time (hemlock)?
How….
How do they reproduce? What is their
growth rate? What is the tolerance of this species to disturbance
(fire, flood, shade, drought, etc.)?

11. Tree Regeneration

12. The full seed reproduction cycle depends upon a number of factors.
There must be resources available to support seed production.
There is actual pollination & seed development.
Seed dispersal
Seed bank – active or dormant
Germination
Seedling bank (persistent juveniles)
Established plant

14. almost all woody plants are capable of some form of cloning, especially aspen, willow, sumac, and dogwood
aspen, cottonwood, many pines, alder
most conifers (except hard pines), hardwoods (upland oak, hickory, basswood, white ash, black cherry)
lodgepole pine, jack pine,
Virginia pine, Monterey pine
cottonwoods, willows, aspen
upland oaks, hickories, walnuts, chestnuts, conifers, firs
shade-tolerant species, Sugar maple, American beech, Hemlock, true firs, western red cedar, Engelmann spruce

15. Pollen cones Seed cones or vegetative shoots
So, primordia located at the base of a shoot tends to become a pollen cone
Near the end of the shoot, it tends to become a seed cone or vegetative shoot
Seed cones or
vegetative shoots

16. F. Noble fir (pollen cones)
Douglas fir
(pollen & seed cones)
Eastern hemlock
Slash pine
(pollen cones)
Bald cypress
(seed cones)
Noble fir (seed cone)
F. Noble fir (pollen cones)
Photos courtesy of the
U.S. Forest Service

17. (Pseudotsuga menziesii )
Douglas fir
(Pseudotsuga menziesii )
Closeup of the underside of a sun foliage shoot of P. menziesii, showing pollen cone buds and the manner of leaf attachment to the twig [C.J. Earle].
Immature seed cone
and active pollen cones
[C.J. Earle, 4-May-2002].
Mature cones
[C.J. Earle].

18. Pinus species Immature Seed Cone Immature Pollen Cones
Pollen Cones (yellow)
&
Seed Cone
(green)
Mature
Seed Cone

19. Distance from forest edge (m) Sound seed deposited (m2)
-20 50
100
150
Sound seed deposited (m2)
1000
2000
3000
4000

20. Primordium = group of cells representing the initial
stages in the development of a plant organ
Primordium is the undifferentiated group of cells
Initiated the growing season of the year before the opening
of the flowers
Overall number of primordia may be the same
from year to year, but the ratio may change.
In initial stages of development.
If a primordium is aborted, there is no trace left.
If latent, forms bud scales and stops
may develop into vegetative shoot later if plant is damaged.
Seed, Vegetative, Pollen
ratio changes from year-to-year based on hormone relations &
internal nutrition.
Lateral buds at the base of a shoot tend to become pollen cones.
Lateral buds at the ends of a shoot tend to become seed cones
or vegetative shoots.

21. Reproductive cycle of Douglas fir
18-month cycle to cone development.
Most seeds develop through the growing season of 2-4 months and are disseminated in fall or winter.
Primordial development
Following year, pollen development, flowering
fertilization
2-4 months of maturation, then disseminated

22. Cone Crop Periodicity Western white pine, northern Idaho 1950 1967
240
120
180 60 51
1950
1967 52 53 54 55 56 57 58 59 61 62 63 64 65 66
Year
Mature Cones
Tree 19
Tree 58
Tree 22
Tree 17
After Rehfeldt et al., 1971
Good cone crops every 3-4 years
Marked drop off after peak production
(1952, 1960, 1963)
Individual trees tend to be on a similar cycle
Considerable variation in inherent productive ability

23. Cone Crop Periodicity 1-2 years - lodgepole pine, willows, Populus
2-3 years – Engelmann spruce, western
hemlock, Quercus
3-5 years – western larch
3-10 years – ponderosa pine, Douglas fir